From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from foss.arm.com (usa-sjc-mx-foss1.foss.arm.com [217.140.101.70]) by dpdk.org (Postfix) with ESMTP id DF290F11 for ; Tue, 4 Sep 2018 10:59:25 +0200 (CEST) Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.72.51.249]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 1DFD17A9; Tue, 4 Sep 2018 01:59:25 -0700 (PDT) Received: from wls-arm-softiron03.shanghai.arm.com (wls-arm-softiron03.shanghai.arm.com [10.169.40.43]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id A15183F614; Tue, 4 Sep 2018 01:59:24 -0700 (PDT) From: "tone.zhang" To: dev@dpdk.org Cc: nd@arm.com Date: Tue, 4 Sep 2018 16:59:07 +0800 Message-Id: <1536051547-8797-1-git-send-email-tone.zhang@arm.com> X-Mailer: git-send-email 2.7.4 Subject: [dpdk-dev] [PATCH] doc: Clarify IOMMU usage with "uio-pci" kernel module X-BeenThere: dev@dpdk.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: DPDK patches and discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 04 Sep 2018 08:59:26 -0000 When binding the devices used by DPDK to the "uio-pci" kernel module, the IOMMU should be disabled in order not to break the IO transmission because of the virtual / physical address mapping. The patch clarifies the IOMMU configuration on both x86_64 and arm64 systems. Signed-off-by: tone.zhang --- doc/guides/linux_gsg/linux_drivers.rst | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/doc/guides/linux_gsg/linux_drivers.rst b/doc/guides/linux_gsg/linux_drivers.rst index 371a817..8f9ec8f 100644 --- a/doc/guides/linux_gsg/linux_drivers.rst +++ b/doc/guides/linux_gsg/linux_drivers.rst @@ -48,6 +48,13 @@ be loaded as shown below: ``vfio-pci`` kernel module rather than ``igb_uio`` or ``uio_pci_generic``. For more details see :ref:`linux_gsg_binding_kernel` below. +.. note:: + + If the devices for used DPDK bound to the ``uio-pci`` kernel module, please make + sure that the IOMMU is disabled. We can add ``intel_iommu=off`` or ``amd_iommu=off`` + in ``GRUB_CMDLINE_LINUX`` in grub on x86_64 systems, or add ``iommu.passthrough=1`` + on arm64 system. + Since DPDK release 1.7 onward provides VFIO support, use of UIO is optional for platforms that support using VFIO. -- 2.7.4